LINQ查询对象列表以获取基于多个字段的分布
我有一个MyBugList使用以下类创建的错误列表
internal class BugDetails
{
public int Id { get; set; }
public string State { get; set; }
public string Severity { get; set; }
}
我想基于State和分组这些错误Severity.我使用以下代码来实现它.
var BugListGroup = (from bug in MyBugList
group bug by new
{
bug.State,
bug.Severity
} into grp
select new
{
BugState = grp.Key.State,
BugSeverity = grp.Key.Severity,
BugCount = grp.Count()
}).OrderBy(x=> x.BugState).ToList();
这个linq查询给出了如下输出
Closed Critical 40
Active Critical 167
Closed Medium 819
Closed Low 323
Resolved Medium 61
Resolved Low 11
Closed High 132
Active Low 17
Active Medium 88
Active High 38
Resolved High 4
Resolved Critical 22
Deferred High 11
但是我想得到如下的输出
Critical High Medium Total
Closed 3 4 5 12
Active 5 4 5 14
Resolved 6 4 5 15
Deferred 1 4 5 10
Total 15 16 20 51
是否可以通过LINQ查询获取MyBugList或打开BugListGroup
我想将输出作为一个列表,以便我可以使它成为一个数据网格源.
注意:State和Severity值是动态的,不能进行硬编码
以下是我在Dmitriy Zapevalov提供的答案的帮助下的实施
private void button1_Click(object sender, EventArgs e)
{
var grouped = MyBugList.GroupBy(b => b.State).Select(stateGrp => stateGrp.GroupBy(b => b.Severity));
//Setting DataGrid properties
dataGridBug.Rows.Clear();
dataGridBug.Columns.Clear();
dataGridBug.DefaultCellStyle.NullValue = "0";
dataGridBug.DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter;
//Declaring DataGrid Styles
var gridBackColor = Color.AliceBlue;
var gridFontStyle = new Font(Font, FontStyle.Bold | FontStyle.Italic);
//Declaring column and row Ids
const string stateColumnId = "State";
const string totalColumnId = "Total";
const string totalRowId = "Total";
//Adding first column
dataGridBug.Columns.Add(stateColumnId, stateColumnId);
dataGridBug.Columns[0].DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft;
//Adding other columns
foreach (var strSeverity in MyBugList.Select(b => b.Severity).Distinct())
{
dataGridBug.Columns.Add(strSeverity, strSeverity);
}
//Adding Total Column
var totColPos = dataGridBug.Columns.Add(totalColumnId, totalColumnId);
var totCol = dataGridBug.Columns[totColPos];
//Adding data to grid
foreach (var state in grouped)
{
var nRow = dataGridBug.Rows.Add();
var severities = state as IList<IGrouping<string, BugDetails>> ?? state.ToList();
dataGridBug.Rows[nRow].Cells[0].Value = severities.First().First().State;
var sevCount = 0;
foreach (var severity in severities)
{
dataGridBug.Rows[nRow].Cells[severity.Key].Value = severity.Count();
sevCount += severity.Count();
}
dataGridBug.Rows[nRow].Cells[totalColumnId].Value = sevCount;
}
//Adding total row
var totRowPos = dataGridBug.Rows.Add(totalRowId);
var totRow = dataGridBug.Rows[totRowPos];
//Adding data to total row
for (var c = 1; c < dataGridBug.ColumnCount; c++)
{
var sum = 0;
for (var i = 0; i < dataGridBug.Rows.Count; ++i)
{
sum += Convert.ToInt32(dataGridBug.Rows[i].Cells[c].Value);
}
dataGridBug.Rows[totRowPos].Cells[c].Value = sum;
}
//Styling total column
totCol.DefaultCellStyle.BackColor = gridBackColor;
totCol.DefaultCellStyle.Font = gridFontStyle;
//Styling total row
totRow.DefaultCellStyle.BackColor = gridBackColor;
totRow.DefaultCellStyle.Font = gridFontStyle;
}
数据网格中的输出看起来像
我做了双重分组：
class Program
{
internal class BugDetails
{
public int Id { get; set; }
public string State { get; set; }
public string Severity { get; set; }
}
static void Main(string[] args)
{
var MyBugList = new BugDetails[]
{
new BugDetails() { Id = 1, State = "Active", Severity = "Critical" },
new BugDetails() { Id = 1, State = "Closed", Severity = "Critical" },
new BugDetails() { Id = 1, State = "Closed", Severity = "Critical" },
new BugDetails() { Id = 1, State = "Closed", Severity = "Critical" },
new BugDetails() { Id = 1, State = "Resolved", Severity = "Critical" },
new BugDetails() { Id = 1, State = "Resolved", Severity = "Critical" },
new BugDetails() { Id = 1, State = "Resolved", Severity = "Critical" },
new BugDetails() { Id = 1, State = "Active", Severity = "Medium" },
new BugDetails() { Id = 1, State = "Active", Severity = "Medium" },
new BugDetails() { Id = 1, State = "Closed", Severity = "Medium" },
new BugDetails() { Id = 1, State = "Closed", Severity = "Medium" },
new BugDetails() { Id = 1, State = "Resolved", Severity = "Medium" },
new BugDetails() { Id = 1, State = "Resolved", Severity = "Medium" },
new BugDetails() { Id = 1, State = "Resolved", Severity = "Medium" },
new BugDetails() { Id = 1, State = "Active", Severity = "High" },
new BugDetails() { Id = 1, State = "Active", Severity = "High" },
new BugDetails() { Id = 1, State = "Closed", Severity = "High" },
new BugDetails() { Id = 1, State = "Closed", Severity = "High" },
new BugDetails() { Id = 1, State = "Closed", Severity = "High" },
new BugDetails() { Id = 1, State = "Closed", Severity = "High" },
new BugDetails() { Id = 1, State = "Closed", Severity = "High" },
};
var grouped = MyBugList.GroupBy(b => b.State).
Select(stateGrp => stateGrp.GroupBy(b => b.Severity));
foreach (var state in grouped)
{
Console.Write("{0}: ", state.First().First().State);
foreach (var severity in state)
{
Console.Write("{0}={1} ", severity.Key, severity.Count());
}
Console.WriteLine();
}
}
}
输出：
Active: Critical=1 Medium=2 High=2
Closed: Critical=3 Medium=2 High=5
Resolved: Critical=3 Medium=3
如果您想使用 DataGridView 显示数据，在这种情况下您可以使用自己的属性集动态创建类型。但这种方式太复杂了。最简单（且性能更高）的方法是手动填充 DataGridView：
private void button1_Click(object sender, EventArgs e)
{
var grouped = MyBugList.GroupBy(b => b.State).
Select(stateGrp => stateGrp.GroupBy(b => b.Severity));
dataGridView1.Columns.Add("State", "State");
foreach (var strSeverity in MyBugList.Select(b => b.Severity).Distinct())
dataGridView1.Columns.Add(strSeverity, strSeverity);
foreach (var state in grouped)
{
int nRow = dataGridView1.Rows.Add();
dataGridView1.Rows[nRow].Cells[0].Value = state.First().First().State;
foreach (var severity in state)
{
dataGridView1.Rows[nRow].Cells[severity.Key].Value = severity.Count();
}
}
}
结果：
